It's a lot more flexible than Jepson suggests using one cable.
Firstly you need a short length of coax with a f connector on each end. Connect tuner 1 out to tuner 2 in.
Download this webpage and open it in your browser.
http://www.4shared.com/document/baZ3...icMK2_011.html
Look at Column 5 labelled block, you will see there are 4 of them marked HBH, HBV, LBH and LBV. These are the 4 modes your lnb can operate in High Band Horizontal, High Band Vertical, Low Band Horizontal and Low Band Vertical.
Now look at Cols 1-5 these show which transponders (multiplexes) are used for the freesat epg channels.
When you set a first recording the channel you are going to record determines which of the 4 blocks the lnb will be using.
Rules You can record any two channels in the same block.
You can also watch some 3rd channels while recording two.
If both recording channels are sharing a transponder then you can watch (and time shift any other channel in the same block)
If both recordings are from different transponders then you can watch (but not time shift) any other channel sharing a transponder with either recording.
Since by far the maJority of tv channels are in the two lower band blocks for most recording situations a little less than 50% of the total channel count can be second recorded. If one of the recording pair is a bbc 1 region then by switching regions you can make over 90% of 2nd channels available.
Example if you use a postcode that gives you ITV1-HD Granada on the epg you can do this
Record BBC1-HD and BBC-HD and view ITV1-HD all at the same time.
When you install the hdr it recognises the single cable mode of connection so it knows which channels are available for recording and viewing.
Of course it makes sense to fit a quad lnb and provide the second cable bit if this is not possible then it's a viable comprimise.
Of course it makes sense to fit a quad lnb if you can to provide the second connection